Doctors Without Borders says an attack by Islamic extremists in Niger's Bosso district has killed at least six people.

The organization, also known in French as Medecins Sans Frontieres, said Wednesday that Boko Haram insurgents attacked a health clinic, destroyed homes, the market and wells that provide water to Yebi village in the May 19 attack. It said without the wells the village has no water supply.

It said the health post there had served about 20,000 people. The group evacuated eight severely injured people to a hospital in the regional capital, Diffa.

Thousands of people displaced by violence in the Lake Chad region have taken refuge in Niger's Diffa region. Some 20 attacks were carried out there between Jan. 1 and March 10.